1. Field of the Invention
This invention is directed to a system for inserting a component part into a product which is moving through an assembly process. More particularly, this invention provides a robotic system for inserting windshields into a vehicle. The vehicle is in motion on a conveyor during the insertion. The windshield is automatically centered for robot acquisition. Multiple sensor information is converted into real time path modification signals for robot guidance so that the windshield can be inserted into the windshield opening of an automobile which is in a somewhat random orientation on a moving conveyor apparatus.
2. Description of the Prior Art
The general acceptance of industry automation as an essential requirement for improving productivity has increased acceptance level of the robot or industrial manipulator apparatus as a mechanism for achieving automated industrial applications. The acceptance of robots as a useful, industrial "tool" has resulted in a market demand for robotic systems capable of implementing what have heretofore been difficult, dangerous or tedious tasks.
The automotive industry presents exceptional opportunities for the use of robots or industrial manipulators for the purpose of improving productivity and enhancing quality of the finished product. What were once routine tasks are now efficiently and effectively being implemented by robots working side by side with their human worker counterparts. For example, robots are now used to apply adhesives and sealing materials to various component parts of an automobile. Robots are also used to move heavy component parts and weld the various component parts of an automobile together as well as to apply paint to the automobile. Certain tasks, however, have heretofore not lent themselves to automation. One example of such a task is the insertion or decking of windshields into vehicles. Several obvious factors have prohibited the automation of the decking process. A high level of accuracy is necessary in order to place the windshield into the windshield opening of the vehicle. A slight miscalculation during the decking process can result in both damage to the vehicle and destruction of the windshield. Additionally, the existing conveyors which transport the automobile through various work stations are relatively unstable and tend to cause a slight change in the precise orientation of the vehicle mounted thereon. Moreover, typically the nearly complete vehicle into which the windshield is to be inserted is positioned on the conveyor apparatus in such a way as not to permit the exact location of the windshield opening to be consistently known. In other words, there is a certain level of random orientation of the vehicle on the assembly line during the stage in which the windshield is to be inserted. As a result, the decking operation has heretofore been accomplished through the use of two or more workmen engaging a windshield with hand-held lifting equipment and walking across the assembly line so that one worker is along each side of the vehicle and manually inserting the windshield into the vehicle windshield opening. This technique has the advantage of precision windshield placement, while permitting the existing conveyor system to continuously transport the vehicle through the decking station. During this process, workmen on either side of the vehicle walk along side the vehicle as it passes through the windshield insertion station while they insert the windshield into the windshield opening.
In order to effect the automated insertion of a component part into a product, it is necessary to initially know the exact orientation and location of the product. With this information, the orientation of a component part can be established and once acquired by an industrial manipulator, the insertion of the component part into the product can be easily and quickly accomplished. However, when a moving conveyor apparatus is used to transport the product to the work station in which the component insertion is to take place, it has heretofore been necessary to either have precise orientation of the product on the conveyor or to simply stop the conveyor for the length of time necessary for the robot to effect the insertion process. Obviously then, if either the orientation of the product is unknown or if the product is subject to somewhat random moves during the conveyance procedure, the insertion of the component part into that product would be very difficult.
A system has been designed incorporating an industrial manipulator using the Unimation Incorporated VAL II controller with alter port. The alter port was used in conveyor tracking in order to track a car being transported down an assembly line on a first conveyor. The industrial manipulator, tracking with the car, picked up part of a car body and moved it from the first conveyor to a second overhead conveyor. While the car was tracked and picked up by a robot and put on the next conveyor through the use of the alter port, any minor differentiation in the positioning of the car body on the first conveyor with respect to the robot was compensated for by a degree of compliancy in the gripper which was used to pick up the car. This system knew the general location of the car on the conveyor and depended upon the compliance of the gripper to engage the car for transport to the second conveyor. This system utilized strictly the tracking of the conveyor with no attempt to identify the exact location of the car disposed thereupon.
It is an object of this invention to provide a system which is capable of tracking a moving object in all coordinate systems. The component is moving up and down and it is shifting from side to side due to the motion of the conveyor apparatus used to transport the car body.
It is another object of the present invention to provide a technique whereby a component part can be inserted into a product having a relatively unknown or unstable orientation on a moving conveyor apparatus.
It is a further object of the present invention to provide an automated system for the insertion of a windshield into a moving vehicle.
It is yet another object of the present invention to provide an automated system wherein a multi-sensor processor provides simultaneous sensor information for conversion into real time path modification signals for robot guidance.
It is still another object of the present invention to provide a windshield insertion system for a moving vehicle which can readily be incorporated with existing conveyor systems in automotive plants.
It is yet again another object of this invention to provide in combination with existing conveyors which continuously transport vehicles without stopping at the insertion stations, a windshield insertion system for inserting windshields into a continuously moving vehicle on a conveyor line.
It is another object of this invention to provide a system which can be used to insert various component parts into a product apparatus such as, for example, back lights and quarter windows, as well as other assembly line parts, into an automobile being transported on a moving conveyor line.
It is another object of this invention to provide a system which is not sensor technology dependent and which can function with various types of robots or automated systems and is insensitive to car or product position and orientation due to of the extensive use of sensors.